Evaluation of Phytochemistry and Pharmacological Properties of Alnus nitida

In the current study, the anti-inflammatory and analgesic potential of Alnus nitida (leaves and fruits) was evaluated in the Sprague-Dawley rat. Traditionally, A. nitida was used for the treatment of inflammatory ailments. However, A. nitida leaves and fruits have not been yet reported regarding any potential medicinal effects. Leaves/fruits of A. nitida were extracted with methanol and fractionated to attain n-hexane, chloroform, ethyl acetate and aqueous fractions. These extracts were then evaluated for in vivo analgesic and anti-inflammatory potential. For in vivo anti-inflammatory activity, carrageenan-induced paw edema assay, Freunds’ complete adjuvant-induced edema, xylene-induced ear edema and histamine-induced paw edema models were used in rats, which showed significant (p < 0.01) reduction (70−80%) in edema in comparison of inflammatory controls. On other hand, for the analgesic assessment, hot plate assay and acetic acid-induced writhing tests were used, which showed a significant (p < 0.01) rise in latency time (40−60%) as compared with pain-induced controls. These results were comparable with standard drugs in a concentration-dependent manner and no mortality or toxicity was observed during all experiments. Then, for the identification of chemical constituents gas chromatography−mass spectrometry (GC-MS) analysis was performed, which indicated the presence of neophytadiene, 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, phytol and vitamin E, justifying the use of A. nitida to treat inflammatory disorders.

Antidiabetic and antioxidant potential of Alnus nitida leaves in alloxan induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Alnus nitida are used by local communities for the management of diabetes and in inflammatory disorders.

METHODS

Powder of shade dried leaves of A. nitida was extracted with methanol (ANME) and fractionated in escalating polarity i.e n-hexane (ANHE), chloroform (ANCE), ethyl acetate (ANEE) and soluble residual aqueous fraction (ANAE). The extract/fractions were evaluated for antidiabetic in vitro assays; α-amylase, α-glucosidase and dipeptidyl peptidase-4 (DPP-4). The in vivo investigations were carried out on ANEE and ANAE (100 mg/kg; 200 mg/kg, p.o.) in alloxan (125 mg/kg i.p.) induced hyperglycemic rats. Serum analysis was performed on liver, pancreas and kidney function markers. Analysis of antioxidant enzymes and genotoxic studies were carried out on pancreas, liver and kidneys tissues. GC-MS analysis was performed on ANME whereas HPLC analysis was carried out on ANME, ANEE and ANAE.

RESULTS

Preliminary in vitro assays indicated appreciable antidiabetic activity of ANEE and ANAE against α-amylase, α-glucosidase and DPP-4 assay. Furthermore, in vivo antidiabetic effect of ANEE and ANAE was inveterate by anti-hyperglycemic action in normal glucose loaded and diabetic glucose loaded animals. Single dose of alloxan (125 mg/kg) decreased the level of insulin and high density lipoprotein while raised the level of amylase and lipase, ALT, AST, total lipids, triglycerides, cholesterol, creatinine, BUN, CPK, CK-Mb in serum. Concentration of H₂O₂, lipid peroxidation (TBARS) and nitrite was increased (P < 0.05) whereas level of tissue protein, glutathione content (GSH) and antioxidant enzymes decreased in pancreas, liver and kidneys as compared to control group. Administration of ANEE and ANAE for 14 days after induction of diabetes decreased the hyperglycemia and restored the level of these parameters. Histopathological and genotoxic studies also endorsed the defensive strategies of ANEE and ANAE. GC-MS analysis of ANME demonstrated the presence of antidiabetic constituents i.e. linalool, Vitamin E and phytol.

CONCLUSION

Results obtained in this study suggests antidiabetic and antioxidant abilities and provides the scientific proof of the folklore medicine.

Potent anti-cancer activity of Alnus nitida against lung cancer cells; in vitro and in vivo studies

Alnus nitida is used for multiple disorders in norther areas of Pakistan. In this study we have evaluated methanol extract of leaf (ANL) and stem bark (ANB) of A. nitida against two lung cancer cell lines; A-549 and H460 (Human non-small lung cancer cell lines) during in vitro assays for growth inhibition. Treatment with ANL and ANB markedly inhibited the growth of both cancer cell lines. Exposure of A-549 and H460 cancer cell lines to ANL and ANB inhibited cell survival, colony growth and migration of cells. Further, treatment of A-549 and H460 with ANL and ANB indicated alteration in actin fibers after staining with rhodamine-phalloidin. Both extracts cause shrinkage and cell cycle arrest during G1 phase. Treatment of A-549 and H460 cancer cells with ANL and ANB repressed the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL along with downregulation of NFκB, cyclin D1 and PI3-K protein. In addition, intraperitoneal injection of ANL and ANB (10 mg/kg bw and 20 mg/kg bw) to C57BL/6 J mice implanted with B16F10 (Mouse melanoma cancer cell line) cells significantly (p < 0.01) decreased the number of nodules per lung and the level of various proteins reciprocating the in vitro studies. These results suggest that ANL and ANB be explored further for therapeutic use in lung cancer.

stem bark in Sprague Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Stem bark of Alnus nitida (Spach) Endl. (family Betulaceae) is used by local communities in northern areas of Pakistan as a remedy for swelling, injuries and pain. However no pharmacological study of this plant has been reported to confirm these activities. In this study anti-inflammatory and analgesic effect of A. nitida stem bark have been evaluated.

METHODS

Powder of the stem bark of A. nitida was extracted with methanol (ANBM) and partitioned in escalating polarity to get the n-hexane (ANBH), chloroform (ANBC), ethyl acetate (ANBE) and the residual soluble aqueous (ANBA) fractions. The methanol extract and derived fractions were evaluated for anti-inflammatory activity by using in vitro heat induced albumin denaturation assay and various in vivo assays; carrageenan-induced hind paw edema method, Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema in Sprague Dawley rat. The extracts/fractions were also evaluated for analgesic effects by using hot plate analgesic test and acetic acid induced writhing test in rat. The ANBM composition was analyzed by HPLC-DAD and GC-MS analysis.

RESULTS

Results of heat induced albumin denaturation activity indicated that among the extract/fractions ANBC at concentration range of 100-500µg/ml remarkably protected the heat induced albumin denaturation. The pretreatment with ANBC significantly reduced the carrageenan induced edema with 90.81±1.6% after 4h, comparing with 86.63±3.42% reduction produced by the reference drug diclofenac potassium. Histopathological alterations of the gastric and hind paw were decreased with the extract/fractions. Furthermore, anti-inflammatory effects of ANBC were evident in Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema. The latency time in hot plate analgesic assay with ANBC (61.59±0.38%) after 90min was comparable to standard drug morphine (69.31±2.67%) and aspirin (67.24±2.08%). Similarly ANBC significantly (p<0.01) inhibited the pain sensation in acetic acid induced writhing test in rat. HPLC-DAD analysis of ANBM indicated the presence of gallic acid, catechin and rutin while the GC-MS analysis of ANBM indicated the presence of 30 compounds predominantly of neophytadiene, 3,7,11,15 tetramethyl-2-hexadecen-1-ol, phytol, vitamin E and linalool.

CONCLUSION

The results of this study suggested that the presence of polyphenols, sterols, terpenoids and other constituents might contributed towards the anti-inflammatory and analgesic activities of the crude methanol extract of A. nitida bark and its derived fractions. This study endorsed the folklore use of A. nitida bark for inflammation related disorders.

Phytochemical, antioxidant and hepatoprotective effects of Alnus nitida bark in carbon tetrachloride challenged Sprague Dawley rats

BACKGROUND

Alnus nitida (Spach) Endl. is traditionally used for inflammatory disorders. Diarylheptanoids constituents having diverse therapeutically importance including hepato-protective was reported in A. nitida. The aim of this study was to explore the antioxidant and hepato-protective profile of A. nitida stem bark's crude methanol extract (ANM).

METHODS

Crude methanol extract of A. nitida stem bark and its derived fractions were assessed for phytochemical classes and in vitro antioxidant profiling by multidimensional assays. Hepato-protective assessment of ANM was investigated on rats, which were made hepatotoxic using carbon tetrachloride (CCl4). Additionally HPLC-DAD analysis of ANM, and its derived ethyl acetate and aqueous fraction was carried out to determine the presence of active constituents.

RESULTS

Qualitative analysis of crude extract-and its fractions depicted the presence of terpenoids, saponins, coumarins, phenols and flavonoids. Maximum quantity of total phenolic content (TPC) and total flavonoid content (TFC) was recorded in ANM and its derived fractions; n-hexane (ANH), chloroform (ANC), ethyl acetate (ANE) and the residual aqueous (ANA). ANM exhibited the best total antioxidant capacity, total reducing power, and scavenging of DPPH and OH radicals. ANE and ANA exhibited strong scavenging potential for iron chelation, nitric oxide and β-carotene bleaching assay. ANM treatment converse the activities of serum-marker enzymes and lipid profile, altered by CCl4 treatment in rat. CCl4 induced hepatic-cirrhosis in rat resulted in decrease of antioxidant enzyme activities such as catalase, peroxidase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase-which were restored towards the normal level with ANM. Similarly diminished level of reduced glutathione while enhanced level of lipid peroxides, hydrogen peroxide and nitrite in liver of cirrhotic rats was normalized by treatment of ANM. The histopathological studies of liver tissues also represented that ANM possessed the hepato-protective activity. HPLC-DAD analysis against eight known standards confirmed the presence of gallic acid, catechin and rutin in ANM and in ANA while in ANE gallic acid was only detected.

CONCLUSION

Based on the results of antioxidants, restoration of various antioxidant enzymes and histopathological studies, the recent study concludes that antioxidant potential of A. nitida bark might protect the liver damages.